Studies of Pathogenicity of Campylobacter jejuni.

1.利用一种新开发的培养基能从腹泻病例中分离出25株空肠弯曲菌产生霍乱样肠毒素。这种新的培养基比以前报道的两种用于此目的的培养基产肠毒素的量更高。霍乱毒素抗血清和大肠杆菌不耐热肠毒素(&lt；LT_h&gt；和&lt；LT_p&gt；)中和了引起中国仓鼠卵巢(CHO)细胞形态改变的毒素活性，表明这两种毒素之间有密切的免疫学关系。空肠弯曲菌/大肠埃希菌培养滤液对CHO细胞的细胞毒作用也被证实，39株空肠弯曲菌中有33株对CHO细胞有杀伤作用，8株大肠埃希菌均有细胞毒性。由于空肠弯曲菌/大肠杆菌产生的毒素的细胞毒活性可以被纯化的志贺毒素抗血清中和，因此我们从志贺氏菌1和大肠杆菌0157：H7中分离纯化志贺毒素和志贺样毒素，以比较它们的结构。我们建立了一种高灵敏度的ELISA法来检测另一种细菌毒素以及弯曲杆菌毒素。该方法对产肠毒素大肠埃希菌不耐热肠毒素的敏感性为200pg/ml，对志贺氏菌1型志贺氏菌毒素的敏感性为60pg/ml，对肠出血性大肠杆菌Vero毒素的敏感性为20pg/ml，对副溶血性弧菌的耐热直接溶血素(TdH)为6pg/ml，对霍乱弧菌的霍乱肠毒素(CT)的敏感性为60pg/ml。

1. By means of a newly developed medium, cholera-like enterotoxin production by Campylobacter jejuni could be shown in 25 C. jejuni strains isolated from diarrheic cases. This new medium was found to yield a higher amount of enterotoxin than the two previously reported media for this purpose. Neutralization of the activity of the toxin to cause morphological changes of Chinese hamster ovary (CHO) cells by antisera against cholera toxin and heat-labile enterotoxins of Escherichia coli ( <LT_h> and <LT_p> ) was also demonstrated, indicating a close immunological relation of these toxins.2. The cytotoxicity of culture filtrates of C. jejuni/coli on CHO cells was also demonstrated with 33 out of 39 C. jejuni and with all 8 C. coli strains.3. Since the cytotoxic activity of the toxin produced by C. jejuni/coli was neutralized by an antiserum against purified Shiga toxin, we purified Shiga and Shiga-like toxins from Shigella dysenteriae 1 and Escherichia coli 0157:H7 to compare the structures.4. We developed a highly sensitive ELISA to detect another bacterial toxins as well as the toxins of Campyrobacter. Sensitivity of this ELISA was 200 pg/ml for heat-labile enterotoxin of enterotoxigenic Escherichia coli, 60 pg/ml for Shiga toxin of Shigella dysenteriae 1, 20 pg/ml for a Vero toxin of enterohemorragic E. coli, 6 pg/ml for thermostable direct hemolysin (TDH) of Vibrio parahaemolyticus, and 60 pg/ml for cholera enterotoxin (CT) of V. cholerae.